Inlet-valve for air-compressors



(No Model.)

R. P; GRIGSBY. INLET VALVE FOR AIR commnssoas.

No. 567,092. Patented Sept. 1, 1896.

firzea 's e Zzvenz' 2056;; 707 65 MM. (B W,

Rs :0. morauruq, WASNINGTDN u c UNITE STATES ATENT FFICEQ ROBERT F.GRIGSBY, OF CALISTOGA, OALIFORNIA, ASSIGNOR OF ONE-HALF TO THE FULTONENGINEERING AND SHIP BUILDING VORKS, OF SAN FRANCISCO, CALIFORNIA.

iNLET-VALVE FOR AlR-COMPRESSORS.

SPECIFICATION forming part of Letters Patent No. 567,092, datedSeptember 1, 1896. Application filed Oct ber 2, 1895. Serial No,564,465. (No model.)

To all whom it may concern:

Be it known that I, ROBERT F. GRIGSBY, a citizen of the United States,residing at Oalistoga, Napa county, California, have invented a new anduseful Inlet-Valve for Air-Oompressors, of which the following'isaspecification.

My invention relates to inlet-valves for aircompressors, and has for itsobject to produce a valve of few parts and great efficiency.

To this end my invention consists of an inlet-valve constructedsubstantially as shown and described, and particularly defined in theclaims.

1 5 In the drawings, Figure 1 is a central sectional view of the entirevalve. Fig. 2 is a sectional plan of the lower half of the valve,looking down into it. Figs. 3 and 4 are detail views of the valveitself.

A is the valve, which is preferably made of aluminium and is constructedin the form of a hollow cylindrical shell having an opening in its upperportion to admit the rod 0. The upper portion of the sides is cut away,leav- 2 5 ing two large openings for admission of air to the interior ofthe valve. Four small openings 5 near the seat of the valve permit theinlet of the air from the valve into the cylinder.

B is the casing, preferably made of bronze or gun-metal, andis boredsmooth and true inside in its lower portion, so that the aluminium valvewill Work smoothly and easily therein. The lower portion of the casingis 3 5 threaded at e e and turned at i i to enable it to be properlysecured in place.

The top of the casing is provided with a threaded opening to receive athreaded rod O. This rod extends down into the center of 40 the casingand through the opening in the top of the valve. The lower end of this-rod is provided with a head having a groove upon its upper flange inwhich is seated one end of awire spring D, which is coiled around therod and extends upward to the top of the valve, where it is seated in agroove encircling the opening through which the rod extends.

A jam-nut E is threaded on the outer extremity of the rod and bears uponthe upper surface of the casing. The rod is provided with a squared endto permit its being turned by a wrench, so as to adjust the tension ofthe spring. 7

The casing B is preferably cut away at its upper portion, so as toformthe arms I), leading down to the threaded portion'e c. Sock-' ets 0 areprovided in the rim of the casing, which are adapted to receive a wrenchto seat the casin g. The valve should be carefully turned and finishedto snugly fit the sleeve and seat of the casing.

By my construction an inlet-valve is produced having only two movingparts, the valve A and the spring D. By making the valve A in theform'of a hollow cylindrical shell, which closely fits the interior ofthe casing for more than half its length, all binding and sticking areavoided, as is common to the ordinary valve provided with a longvalvestem. By reason of its cylindrical form the valve is free to rotatearound the rod O in operation, thus always maintaining a true seat. Thesimple arrangement of the threaded rod 0 permits the tension of thespring upon the valve to be easily and speedily regulated while thevalve is working, andan entire set of valves can thus be brought to anequal working tension while the compressor is in operation. By locatingthe spring as shown and described the valve is perfectly balanced, thuspreventing the dropping down of the valve, which is a common defect inthe ordinary modes of construction. While in its normal or closedposition the spring offers very slight resistance, and this, togetherwith the extreme lightness of the valve by reason of its form andmaterial, renders it very easy to move, offering only about one-thirdthe resistance of ordinary valves. A valve thus constructed has beenfound by actual experi- 9o ment to be especially efficient as aninletvalve for air-compressors.

What I claim is- 1. An inlet-valve for air-compressors consisting of acasing B having its lower portion 5 bored smooth and true, a cylindricalvalve A closely fitted in the said lower portion of said casing and atension-regulating device substantially as described extended into saidcasing and into said valve, the construction and 10 arrangement beingsuch that the valve is free to rotate in its casing. v

2. An inlet-valve for air-eo1npressors consisting of a casing B havingits lower portion bored so as to truly guide and seat the valve, a rod 0secured to the upper portion of the casing and extended downwardlytherein, a hollow cylindrical valve A working in said casing and aroundthe said rod, and a spring D carried by said rod and bearing against theupper and inner face of the valve, substan tially as and for the purposedescribed.

3. An inlet-valve for air-compressors consisting of a casing B havingits lower portion constructed to guide and seat an aluminium valve, arod adj ustably threaded in the upper

